Match two planes with different origin locations (Blender Python Matrix Math)
Face centre as "Pseudo Origin"

Given we have 2 single face planes, will make the face centre the "pseudo origin" and match that. 

Test script, moving "Plane.001" to "Plane".  The difference in face centre coordinates vector is used to create a local transformation matrix. Premultiplying this by the matrix world will translate the "face centres" to match.  

import bpy
from mathutils import Matrix
context = bpy.context
scene = context.scene
# going to match transform of p2 to p1
p1 = scene.objects["Plane"]
mw = p1.matrix_world
p2 = scene.objects["Plane.001"]

# local offsets
o1 = p1.data.polygons[0].center
o2 = p2.data.polygons[0].center
# match the face centers global coords
# local translation matrix
LTM = Matrix.Translation(o1 - o2)
p2.matrix_world = mw * LTM